Scale assembly for providing improved accuracy during metering of fluid from a liquid or gas delivery tank

Abstract

A scale assembly for determining a weight and converted volume of fluid and gas withdrawn from a tank. A plurality of lift cylinders and cam linkages are arranged in paired and perimeter spaced fashion about a perimeter of the tank in extending fashion through an associated support flange. The cam linkages are normally biased in a first position to restrain the tank into contact with the support surface, the linkages being actuated in a second position to release the tank for subsequent elevation by the lift cylinders. A load cell is arranged in communication between each of the lift cylinders and the pallet support surfaces and, upon being recalibrated following tank elevation, measures the weight and converted volume of the delivered fluid.

I claim: 
     
       1. A scale assembly for determining a weight of a fluid withdrawn from a tank arranged upon a support surface, said assembly comprising:
 at least one lift cylinder in contact with both the support surface and a flange associated with a lower support location of the tank; 
 at least one cam driven linkage adapted to being mounted to the support surface and which is normally biased in a first position so as to contact an upper surface of the flange to restrain the tank into contact with the support surface, said linkages being actuated in a second position away from the upper flange surface to release the tank for subsequent elevation a distance above the support surface upon actuation of said lift cylinders; and 
 a load cell arranged in communication between each of the lift cylinders and the support surface, said cell communicating with an electronic scale which is recalibrated prior to withdrawing fluid from the tank and in order to subsequently measure at least a weight of the fluid delivered therefrom. 
 
     
     
       2. The scale assembly as described in  claim 1 , further comprising a plurality of lift cylinders and cam linkages arranged in paired and perimeter spaced fashion about a perimeter of the tank in extending fashion through the support flange. 
     
     
       3. The scale assembly as described in  claim 1 , each of said lift cylinders further comprising a covering cap incorporating an air cylinder positioned above said load cell, a lower extending load cell button associated with said load cell seating within a recess associated with an upward projecting cone forming an aligning platform support location. 
     
     
       4. The scale assembly as described in  claim 3 , further comprising each of said load cells each being displaceable relative to an inner vertical surface of said covering cap to avoid compromising the accuracy of the digital reads resulting therefrom. 
     
     
       5. The scale assembly as described in  claim 3 , further comprising said covering cap being bolted to a base of the tank flange in surrounding and aligning fashion with an interior aperture of the flange and through which upwardly projects said seating cone. 
     
     
       6. The scale assembly as described in  claim 5 , further comprising upper located mounting bolts for securing said air cylinder to the upper inner end of said cap. 
     
     
       7. The scale assembly as described in  claim 6 , further comprising a nipple engageable attachment fitting projecting from said air cylinder through said cap and adapted to receive a pressurized air supply. 
     
     
       8. The scale assembly as described in  claim 7 , further comprising a separate fitting extending from said load cell and projecting through an opening defined in the vertically extending sidewall of said covering cap, said fitting adapted to being connected by an input associated with said scale. 
     
     
       9. The scale assembly as described in  claim 1 , each of said cam linkages further comprising a spring loaded cylinder establishing a pivotal interconnection at a lower end with a pedestal support bracket, and at an upper end with a lever arm, in turn established in rotary engagement with a cam associated with a shaft extending between end supports which are likewise supported upon the support surface and extend through additional aligning apertures in the flange associated with the lower tank supporting location. 
     
     
       10. The scale assembly as described in  claim 9 , further comprising a pressurized fluid source communicated to said spring loaded cylinder to counter-act a rotating force exerted by said spring cylinder against said cam in a normally hold down or locking position and in order to execute a counter rotation to thereby rotate unseat an abutting ledge surface of said cam from a hold-down contact established with an upper surface of said tank support flange to a release position, allowing for subsequent elevation of the tank by said lift cylinders a nominal distance sufficient to zero out a digital scale module and to permit measurement of withdrawn fluid, with weight to volumetric conversion to determine a volume of fluid delivered to the customer, upon termination of the air pressurization force to all said lift cylinders and said spring loaded cylinder, the tank and flange re-seating upon the pallet support location and said spring loaded cylinder rotating said cam back into hold-down position in a fail-safe lock mode. 
     
     
       11. The scale assembly as described in  claim 1 , each of said cam linkages further comprising a rotary actuator exhibiting a three dimensional rectangular housing, through which extends a cylindrical cross sectional and elongated support, a cam component supported upon an exterior face of said rotary actuator and through which extends a further shaft with a keyed end, the same being in turn supported by a pillow block bearing for providing an optional extra degree of support. 
     
     
       12. The scale assembly as described in  claim 11 , further comprising said cam being rotated over a desired angular range in order to provide either hold-down or release of the fluid delivery tank to be elevated by said perimeter located air cylinders. 
     
     
       13. The scale assembly as described in  claim 12 , each of said cam linkages further comprising a horizontally disposed wedge component arranged in end displaceable engagement with a spring containing air lift cylinder, said lift cylinder pivotally supported to a bracket in turn is mounted to a surface location of the underlying pallet and which passes through an aligning recessed defined in said flange support location associated with said tank. 
     
     
       14. The scale assembly as described in  claim 13 , further comprising said spring containing air cylinder, upon being provided with an input pressurized fluid source, causing said wedge component to retract, via an intermediate pivotal interconnecting structure mounted to the end of a linearly displaceable shaft associated with said spring loaded cylinder. 
     
     
       15. The scale assembly as described in  claim 14 , further comprising a seating pocket defined in a superstructure projecting upwardly from the pallet and seating through an aperture in said tank support flange such that, in a fluid pressurizing (energized/retracted) position, forward most extending fingers of said wedge component are unseated from the seating pocket and such that, in the retracted position, align only through a doorway defined in a tower also projecting from the pallet and seating through a further aperture in said tank support flange, said tower being arranged in spaced aligning fashion with said superstructure. 
     
     
       16. A scale assembly for determining a weight of a fluid withdrawn from a tank arranged upon a support surface, said assembly comprising:
 at least one lift cylinder in contact with both the support surface and a flange associated with a lower support location of the tank; 
 at least one cam driven linkage adapted to being mounted to the support surface and which is normally biased in a first position so as to contact an upper surface of the flange to restrain the tank into contact with the support surface, said linkages being actuated in a second position away from the upper flange surface to release the tank for subsequent elevation a distance above the support surface upon actuation of said lift cylinders; 
 each of said cam linkages further including a spring loaded cylinder establishing a pivotal interconnection at a lower end with a pedestal support bracket, and at an upper end with a lever arm, in turn established in rotary engagement with a cam associated with a shaft extending between end supports which are likewise supported upon the support surface and extend through additional aligning apertures in the flange associated with the lower tank supporting location; and 
 a load cell arranged in communication between each of the lift cylinders and the support surface, said load cell communicating with an electronic scale which is recalibrated prior to withdrawing fluid from the tank and in order to measure at least a weight of the fluid delivered therefrom. 
 
     
     
       17. A scale assembly for determining a weight of a fluid withdrawn from a tank arranged upon a support surface, said assembly comprising:
 at least one lift cylinder in contact with both the support surface and a flange associated with a lower support location of the tank; 
 at least one cam driven linkage adapted to being mounted to the support surface and which is normally biased in a first position so as to contact an upper surface of the flange to restrain the tank into contact with the support surface, said linkages being actuated in a second position away from the upper flange surface to release the tank for subsequent elevation a distance above the support surface upon actuation of said lift cylinders; 
 each of said cam linkages further including a rotary actuator exhibiting a three dimensional rectangular housing, through which extends a cylindrical cross sectional and elongated pressurized cylinder incorporating rack and pinion gears, a cam component supported upon an exterior face of said rotary actuator and through which extends a further shaft with a keyed end, the same being in turn supported by a pillow block bearing for providing an optional extra degree of support; and 
 a load cell arranged in communication between the lift cylinders and the support surface, said scale being recalibrated prior to withdrawing fluid from the tank and in order to measure at least a weight of the fluid delivered therefrom.